Renewable sleeve for rotatable shafts.



APPLICATION FILED AUG-5. 1914.

Patented May 11, 1915/ HOWARD HOFFMAN, OF BELMAR, NEW JERSEY.

RENEWABLE SLEEVE FOR ROTATABLE SHAFTS.

To all whom it may concern:

Be'it known that I, HOWARD HOFFMAN, a citizen of the United States,residing in Belmar, in the county of Monmouth and State of New Jersey,have invented certain new and useful Improvements in Renewable Sleevesfor Rotatable Shafts, of which the following is a specification.

My present invention relates to an im-' provementin renewable sleevesfor shafting as applied to vessels of the motorboat class. Its use mayalso be so extended as to include other types of power driven vesselsand also to rotating shafting of all kinds, where the wear of the shaftand the consequent reduction of cross sectional area is greater thanunder ordinary use. As is well known in the above noted class of vesselsit is oustomary to have the propeller shaft of Tobin bronze or othernon-corrodible material and at the stern of the vessel where thepropeller leaves the boat and enters the water there is arranged ametallic bearing for the shaft, which bearing also performs thefunctionof a stufling box for preventing leakage of the water into the boat.

In stufling boxes of the usual type a packing nut is used forcing thepacking against the bronze shaft, in order to make a water tight fit,and the shaft after a while becomes badly grooved or worn from thepressure of the packing thereon, thereby permitting water to enterthrough this leaky connection. Fresh packing may be inserted into thestuffing box' and compressed against the worn shaft to tighten thebearing, until the grooves finally become so deep in the propeller shaftthat it is ruined and practically becomes useless, because the shaft isweakened in cross sectional area and the stuffing box cannot be kepttight. Owing to the deep grooves and the inability to keep the jointtight at the worn portion, the shaft must be. replaced by a new onewhich makes the remedy for a. leaky propeller shaft expensive.

In order to economically overcome the difiiculties involved in keeping atight pro peller shaft connection and to save the costly renewals of theshaft, I have designed a renewable sleeve which is looked upon thepropeller shaft, and rotates therewith, in such a manner that it may beshifted from time to time so as to locate the worn place on the sleeveoutside of the stufling box and to bring into the stuifing box a newunworn surface and if the sleeve becomes too badly Specification ofLetters Patent.

grooved for further use it may be readily discarded and replaced by anew one. It is obvious that this method of renewal of the rotativesurface of the shaft is a great and desirable economy.

In the accompanying drawings, Figure 1 is a sectional view of my device.Fig. 2 is an end view thereof and Fig. 3 is another sectional viewshowing the sleeve in another position.

By referring to the accompanying drawings, it will be noted that thepropeller shaft 1 has mounted thereon a sleeve '2, which sleeve 2 has anintegral hexagonal portion 3 thereon for manipulation with a wrench, andadjacent to the same is a cylindrical threaded portion 4: which isformed into a tapered end 5. The tapered end 5 is slotted in a pluralityof places as indicated at 6 and 7, this slotting being for the purposeof rendering the end connection 5 flexible. A look nut 8 having athreaded portion 9 and a tapered seat portion 10 is arranged to bescrewed up upon the thread and tapered end Patented May 11, 1915.

Application filed August 5, 1914. Serial No. 855,109.

of the sleeve in such a manner as to compress the tapered end 5 andcause it to frictionally engage the propeller shaft 1. This causes thesleeve to become substantially a portion of the shaft and to rotatetherewith.

The stufling box here shown is of the well known standard type andcomprises' a flanged and threaded bushing portion 11 having a packingchamber 11 and a packing nut 12 screwed thereon and a lock nut 13 tolock said packing nut in any required position. Packing 13 is shown inthe chamber 11.

In practice, the use of my device renders it necessary to use a sizelarger standard stuffing box than is customarily used; for instance, ifa one inch bronze shaft is used the renewable sleeve member may be oneand onefourth inches outside diameter thereby making the walls of therenewable sleeve about one-eighth inch thick. Therefore a one andone-fourth inch standard bushing will be required for a one inch shaft.If, after a sleeve has been once properly set and the packing compressedto exclude the water, and during use, a slight no longer useful. Thelock nut 8 may be until the sleeve is replaced by a new one.

It is obvious from the foregoing that aside from the advantages obtainedas above noted that the strength of the propeller shaft 1 is greatlyaccentuated by the enveloping sleeve 2 against bending. A motorboat maysometimes be driven in shallow water or against some other submergedobstacle and the propeller coming in contact with such obstacles willforce the shaft upwardly and bend the same close to the'stuifing box. Mydevice gives greater strength and elasticity at this critical point andis an aid to overcoming the foregoing noted disadvantages.

Having thus described my invention, I claim:

1. A shiftable sleeve for shafts comprising a cylindrical portion, awrench receiv ing portion, a threaded cylindrical portion, and a taperedportion slotted to permit of frictional engagement with a shaft.

2. A shiftable removable bearing sleeve for shafts comprising acylindrical portion, a wrench receiving portion, a threaded cylindricalportion, a slotted tapered portion, and a taper chambered nut having acylindrical threaded portion adapted to engage said threaded and taperedportions of said sleeve thereby to permit frictional engagement betweensaid sleeve and a shaft.

3. A shiftable removable bearing sleeve for shafts comprising acylindrical portion, a slotted tapered portion at one end thereof, and acylindrical threaded portion adjacent to said slotted tapered portion;and a nut having a cylindrical threaded portion to engage thecylindrical threaded portion of said sleeve, and a taper chamberedportion to simultaneously engage the slotted tapered portion of saidsleeve thereby to permit frictional engagement between said sleeve and ashaft.

4:. The combination with a stufling box, of a shiftable shaft protectingsleeve on said shaft and in said stufling box, and shaft engaging meanscarried by said sleeve to permit its rigid engagement in any adjustedposition on a shaft, the sleeve being-axially shiftable so as to replacea worn surface of said sleeve in said stuffing box by a fresh surface;

5. The combination with a stufling .box and a shaft, of a shiftablesleeve therebetween, one end of said sleeve being threaded and having aslotted tapering portion and a taper seated lock nut for said end,whereby said sleeve may be locked, unlocked and moved relative to saidstuifing box and shaft to replace a-worn by an unworn surface.

6. The combination with a stuffing box and a shaft extendingtherethrough, of a shiftable sleeve mounted on said shaft and interposedbetween said stufling box and shaft, and means for locking said sleeveon said shaft.

7 The combination with a stufling box and a shaft extendingtherethrough, of an elongated sleeve mounted on said shaft andinterposed between said stutfing box and said shaft, and means forlocking said sleeve to rotate with said shaft, said sleeve beingshiftable between said shaft and stuffing box when the locking means arereleased so as to replace a worn surface of said sleeve in said stuflingbox by a fresh surface.

8. The combination with a stuffing box and a shaft, of an elongatedsleeve mounted on said shaft and interposed between said stuffing boxand said shaft to receive the wear caused by the rotation of said shaftin said stuffing box, said sleeve being axially shiftable so as toreplace a worn surface of said sleeve in said stufing box by a freshsurface.

9. In a device of the character described, a stuflin box, a shaftrotatably mounted in said stu g box but fixed in its axial movementrelative to said stuffing box, and a sleeve mounted on said shaft andinterposed between said stufiing box and said shaft to receive the wearcaused by the rotation of said shaft in said stuffing box, said sleevebeing axially shiftable so as to replace a box by a fresh surface.

10. In a device of the character described, a stuflin box, a shaftrotatably mounted in said stung box but fixed in its axial movementrelative to said stuffing box, a sleeve mounted on said shaft andinterposed between said stuffing box and said shaft to receive the wearcaused by the rotation of said shaft in said stuffing box, said sleevebeing axially shiftable so as to replace a worn surface of said sleevein said stufiing. box by a fresh surface, and means forlocking saidsleeve in position on said shaft against axial J. F. V. CHRISTOPHER.

